Crushing or pulverizing mill.



No. 769,740. PATENTED SEPT. 13, 1904. E. G. GRIFFIN.

CRUSHING 0R PULVBRIZING MILL.

APPLICATION FILED FEB. 13, 1904.

no MODEL. 1 2 SEEETSSHBET 1.

17 220120 (1. Gfv'y'jp'vv, 7 ,7

No. 769,740. PATENTED SEPT. 13, 1904 E. G. GRIFFIN.

CRUSHING OR PULVERIZING MILL.

APPLICATION FILED r1113. 13, 1904.

Nb MODEL. 2 SHEETSSHBET 2 77 50 6 a 4/ iv a 663d" 66-. lzzvemZZr.

l'Ydwzlna G7 1170,

UNITED STATES Patented September 13, 1904.

PATENT OFFICE.

CRUSHING OR PULVERIZING MILL.

SPECIFICATION forming part of Letters Patent No. 769,740, datedSeptember 13, 1904.

Application filed February 13, 1904. Serial No. 193,366- (No model.)

To (1/7] whom, it ntay concern.-

Be it known that I, EDWIN O. GRIFFIN, a subject of the King of GreatBritain, and a resident of N ewton,county of Middlesex, State ofMassachusetts, have invented an Improvement in Crushing or PulverizingMills, of which the following description, in connection with theaccompanying drawings, is a specification, like letters and figures onthe drawings representing like parts.

This invention relates more particularly to the so-called centrifugalroller-mill type of apparatus for crushing or reducing material torequired fineness by subjecting such material to the impact of one ormore rolls traveling upon an annular die, the roll or rolls having axialrotation as well as bodily rotation with relation to the die.

In another application, Serial No. 166,805, filed by me July 24, 1903, Ihave shown certain novel features, including the mode of suspending thecrushing-roll from the revoluble driving-shaft and means to shield therollbearing as much as possible from the entrance of dust'and grit.

My present invention has for its object the production of simple andeffective means for still more effectually shielding from dust and gritthe roll-bearingin a mill of the type substantially as referred to, theconstruction and arrangement of parts being such that a strong andcontinuous downdraft is induced around the rollbearing while the mill isin operation.

The various and novel features of my invention will be fully describedin the subjoined specification and particularly pointed out in thefollowing claims.

Figure l is a half front elevation and vertical section of a crushing orpulverizing mill embodying one form of my invention, the sectional halfbeing taken on the line 1 1, Fig. 2. Fig. 2 is a partial top or planView, enlarged, showing a part of the carrier from which therollsupporting spindle is suspended, with the hood or top of the shieldfor the roll-bearing. Fig. 3 is a front elevation of the parts of theapparatus illustrated in Fig. 1, the depending portion of the shieldbeing shown in section. Fig. i is an inner rear view of thespindle-head, showing the construction thereof, whereby the spindle-headcan rock Without interference by the hood; and Fig. 5 is a sectionaldetail taken on the line 5 5, Fig. 2, with the spindle, spindle-head,and cap omitted.

Referring to Fig. 1, the bed B, having an upturned curb B' and pan Bsustains the annular die D, and an imperforate cylindrical easing Msurrounds an upright screen S, erected around the top of thegrinding-chamber, an A-shaped frame being erected upon the bed andcomprising upwardly-converging standards F, connected by cross-girths Fand F.

The vertical roll-driving shaft C is mounted in suitable bearings E inthe crossgirths and has an attached pulley C driven by a belt from asuitable source of power, the standards F being held in true uprightposition by lateral tension-bracesf; but the detailed construction ofthe parts specified forms no part of my present invention, as they forma portion of the subject-matter of my application, Serial No. 166,805,referred to.

A disk-like carrier 0 is rigidly secured to the lower end of the shaft,the hub a of the carrier supporting an upturned guard 0*", surroundingthe lower end of the bearing E to protect it from the material to beground introduced to the gririding-chamber through the hopper H,supported on the cross-girth F A feed-duct lo, having a flared or bellmouth [6 is bolted to the top of the carrier and surrounds the hub a",the bell-mouth surrounding the lower end of the hopper H, a portion ofthe feed-duct being radially extended at h Figs. 2 and 3, to convey thematerial to the feed-opening J" in the carrier.

One or more centrifugally-acting crushing or pulverizing rolls R aresuspended from the carrier C near its periphery, and each roll iscentrally socketed at /X, Fig. 1, to receive the lowerend of theroll-spindle T, having an annular enlargement f at the upper end of thebearing-hub r of the roll.

The roll is rotatably connected with and retained upon the spindle by acoupling t, bolted to the roll and shaped to overhang the spindleenlargement 6 the upper end of the coupling being elongated to form atubular rection of the rotation of the carrier.

guard t, whose upper end is adjacent the spindle-head N and projectinginto a depending circular flange a thereon.

The spindle-head has a hub n the opposite ends of which are laterallyextended between ears 0 on the carrier (see Fig. 3) and pivoted ona'fulcrum-pin 28, supported in the ears, so that the roll-spindle,rigidly secured to the spindle-head, can swing toward and from thevertical center of the mill, the construction so far described beingsubstantially all as shown in my application referred to, the partsoperating as therein set forth.

A hollow cap N is screwed upon the threaded upper end of the spindle,the cap serving as an oil-reservoir, the roll-spindle having alongitudinal central duct i (see dotted lines, Fig. 1,) opening into thesocket T and a short wick-tube 6 is inserted in the upper end of theduct, projecting into the cap, so that oil therein can be taken up by awick in the tube and permitted to drip through the duct to lubricate theroll-bearing, the roll B being rotatably mounted on the spindle.

I will now describe the novel means forming the subject-matter of thisapplication for forcibly directing air down through the carrier C Theback of the spindle-head has formed upon it a diagonal curvedbearing-surface 12 (see Fig. 4,) which when the cap is screwed downjoins a similarly-curved and diagonal surface a, formed on the back ofthe cap and at one side thereof, the curvature of the two surfaces thenforming a continuous are struck from the center of the pin 28 as acenter. This curved surface cooperates with a portion of the stationaryhood to be described forming a part of the shield for the roll-bearing,as will be explained.

The carrier 0 is apertured at (1 (see clotted lines, Fig. 2) to receiveeach spindle-head, and a tubular shieldM is bolted to the carrier ineach of said apertures C the shield surrounding the spindle and couplingbetween the carrier and the top of the roll, as clearly shown in Figs. 1and 3. The shield thus depends from the carrier and extends well downbelow the upper end of the tubular guard t. as shown clearly in Fig. 1.the inner portion of the shield behind the spindle being elevated abovethe main portion of the carrier, while the outer part of the shieldcomes up close to the dropped-down and laterally-extended peripheralportion 0 of said carrier.

In order to greatly increase the force and intensity of the downdraft orair-blast through the carrier C and shield M, (which blast prevents theentranceof dirt or grit to the rollbearing,)1 have mounted-on thecarrier a hood at the upper or inlet end of each shield, the hood havingits open mouth turned in the di- The back wall of the hood is formed bya portion of the cylindrical part/z of the feed-duct and its bell-mouthif, a shoulder (see dotted lines, Figs. 2 and 5) being formed on theexterior of said parts and extending from the upper edge of thebell-mouth downward diagonally to the carrier C A boss 7 6 is formed atthe upper end of this shoulder, and the inner edge of the hood-top 71/rests on the shoulder and is secured to the boss 76 bya bolt 77. (SeeFigs. 2 and 5.) The outer edge of the top is bent over at 71. andsecured to the top of the upright outer wall it" of'the hood, as byrivets 78. The top it extends to the leading side at of the cap N saidside being made vertical adjacent the bearing-surface 91 and then thehood-top is cut out to present a rearwardly-extended edge 71, whichjoins the back edge [1 of the cut-out portion. Such back edge 72 isinclined and also made concave in the direction of its length to fitagainst the bearing-surfaces n n, the lower end of said edge 72/terminating at the top of the carrier C The hood-top it is thenflattened, as at it, to rest upon the carrier and is secured thereto bya bolt 81, Fig. 2, and by reference to this figure it will be seen thatthe flat portion extends forward and has a straight edge A adjacent thevertical side 71 of the spindle-head N.

As shown in Fig. 5, the inner upright end h of the outer wall 72 of thehood is substantially vertical, and by reference to Fig. 2'

it will be seen that the upper part of the spindle-head N and the cap Nextend into the reentrant or cut-out portion of the top H of the hood.The vertical side 72. of the cap wipes over the edge h of the hood-topwhen the spindle-head rocks on its fulcrum 28, and the concave anddiagonal edge if of the top contacts with the bearing-surfaces n n, sothat the reentrant portion of the hood-top is maintained closed, whilepermitting the radial swing of the roll-spindle. Similarly, the edge 71of such reentrant portion of the hoodtop contacts with the vertical sidea of the spindle-head.

The open end or mouth of the hood is bounded by the carrier-top, theleading edges of the wall it and hood-top 72 and by the parts h if ofthe feed-duct, such mouth being open in the direction of rotation of thecarrier, (indicated by arrow 100, Fig. 2.) As

the carrier is revolved by the shaft C the air rushes into the largeopen end or mouth of the hood and to the contracted rear end thereof,passing thence down through the shield M, the air being forced downthrough the latter with much power and speed, varying with the speed ofrotation of the roll-driving shaft C. This downdraft or blasteffectually prevents the entrance of grit or dirt to the roll-bearing,and consequently reduces wear and tear of the parts.

By reference to Fig. 41 it will be seen that the longitudinal axis ofthe roll-spindle is not at right angles to the fulcrum-pin 28,- the centthe cooperating edges of the top of the hood when the roll-spindleswings on its fulcrum 28.

I have described in detail but one hood and the cooperating parts; butit is to be understood that a plurality of crushing-rolls and theirspindles may be employed, usually three, arranged equidistant from eachother, and each roll-spindle will be provided with a hood, andpreferably with a shield, substantially as hereinbefore described.

In some cases the shield may be changed in its particular shape ordimensions without departing from the spirit and scope of my invention,and in treating some kinds of material the shield maybe omitted, thegist of the invention residing in forcing a blast or strong draft of airdown through the carrier and around the roll-spindle to drive awaytherefrom dust, grit, or small ground particles of material within thegrinding-chamber.

Such details of construction herein shown and described as are common tomy pending application above referred to are not claimed herein, as theyare fully described and properly claimed in such other application.

My present invention may be varied or modified in different particularsby those skilled in the art without departing from the spirit and scopeof my invention.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is*

1. In a mill of the class described, agrinding-chamber containing anannular die, an overhead revoluble carrier, a crushing-roll, a spindleoperatively connected therewith, and fulcrumed on the carrier, a tubularshield surrounding the spindle and mounted on the carrier, the lower endof the shield opening into the grinding-chamber and its upper endopening through the carrier,and means mounted on the latter andcommunicating with the upper end of the shield to collect and force adownblast of air through the shield.

2. In a mill of the class described, agrinding-chamber containing anannular die, an overhead revoluble carrier, a crushing-roll, a spindleoperatively connected therewith and fulcrumed on the carrier, a tubularshield surrounding the spindle and mounted on the carrier, the lower endof the shield opening into the grinding-chamber and its upper endopening through the carrier,and a hood mounted on the latter andcommunicating with the upper end of the shield, the hood having its openmouth in the direction of rotation of the carrier.

3. In a mill of the class described, a grinding-chamber containing anannular die, an overhead revoluble carrier, a crushing-roll, a spindleoperatively connected therewith and fulcrumed on the carrier to swing ina plane radial thereto, the upper end of the spindle projecting abovethe carrier, a tubular shield surrounding the spindle and dependingbelow the carrier and rigidly attached thereto, the lower end of theshield opening into the grinding chamber and its upper end openingthrough the carrier, a hood mounted on the latter and communicating withthe upper end of the shield, the mouth of the hood opening in thedirection of rotation of the carrier, said hood having its outer walland top out out around the upper end of the spindle, and a curvedbearing-surface movable with the spindle and concentric with itsfulcrum, in contact with the top of the hood at the cut-out portionthereof.

:L. In a mill of the class described, a grinding-chamber containing anannular die, an overhead revoluble carrier, a crushing-roll, a spindleoperatively connected therewith, a head secured to the upper end of thespindle and fulcrumed on the carrier to permit radial swinging movementof the spindle, a cap connecting the spindle and head and on top of thelatter, said cap and head having diagonal, curved bearing-surfaces ontheir rear sides concentric with the spindle-fulcrum, a tubular,depending shield attached to the carrier and surrounding the spindle,the lower end of the shield opening into the grinding-chamber and itsupper end opening through the carrier, and a hood mounted on the carrierand having its mouth open in the direction of rotation of the carrier,said hood communieating with the upper end of the shield, the top of thehood being cut out to receive the spindle-head and cooperating with thebearing-surfaces of the head and cap, to permit swinging movement of thespindle while maintaining the hood-top closed.

5. In a mill of the class described, a grinding-chamber containing anannular die, an overhead revoluble carrier, a crushing-roll, asupporting-spindle therefor depending from and mounted to swing on thecarrier, a tubular shield mounted on and depending from the carrier andsurrounding the spindle, the lower end of the shield opening into thegrinding-chamber, and a hood mounted on the carrier and having acontracted outlet end communicating with the upper end of the shield,the enlarged inlet end or mouth of the hood being turned in thedirection of rotation of the carrier, whereby a blast or current of airis collected by the hood and rapidly forced down through the shield intothe grindingchamber.

6. In a mill of the class described, a grinding-chamber containing anannular die, an overhead revoluble carrier having an opening therein, atubular shield depending from the carrier and opening at its lower endinto the grinding-chamber, and at its upper end opening through theaperture in the carrier, a spindle fulorumed on the carrier, andextended downward through the aperture therein,

a crushing-roll rotatably mounted on the lower end of the spindle, ahood on the carrier having its inlet end or mouth open in the directionof rotation of the carrier and with its outlet in communication withthe'upper end of the shield, the latter surrounding the rollspindle andpermitting swinging movement thereof, the outer side and top of the hoodbeing cut away, and means mounted on the upper end of the spindle tocooperate with such cut-away portions of the .hood to close the samewhile permitting free swinging movement of the spindle with relation tothe carrier.

7. In a mill of the class described, a grinding-chamber containing anannular die, an

